A phosphorus removal device with zirconium-modified anion exchange resin

Abstract

The present invention relates to a dephosphorization device with a zirconium-modified anion exchange resin, comprising a fixed bracket and a filter frame, wherein the filter frame is mounted on the fixed bracket; a resin loading module is detachably mounted in the filter frame, wherein the resin loading module has a thickness of 2-10 cm and includes a first side and a second side, wherein the first side is densely covered with honeycomb filter channels, the filter channels extend along the thickness direction of the resin loading module and reach the second side, and the inner diameter of the filter channels is gradually reduced or gradually reduced to a minimum inner diameter before being expanded along the thickness direction of the resin loading module; the maximum inner diameter of the filter channels is 8-12 mm, and the minimum inner diameter is 2-4 mm; the filter channels are filled with 0.15-0.35 mm of zirconium-modified anion exchange resin, and the filling amount is 60-85%; and non-woven fabrics are composited on both sides of the resin loading module. The dephosphorization device of the present invention can quickly adsorb phosphorus in sewage, with a fast dephosphorization speed and stable dephosphorization efficiency.

Description

Technical Field

[0001] The invention belongs to the field of sewage treatment, and in particular relates to a phosphorus removal device with zirconium-modified anion exchange resin. Background Art

[0002] Phosphorus is an essential element for living organisms, and the excessive discharge of phosphorus-containing wastewater will lead to eutrophication of water bodies, causing a series of water ecological environmental damage problems. At present, the main methods for removing phosphorus from wastewater are biological, chemical and adsorption methods. Biological phosphorus removal relies on the metabolism of microorganisms, has high requirements for the environment, and changes in water quality have a greater impact on the phosphorus removal effect. Chemical phosphorus removal requires the addition of a large amount of chemical reagents, which is costly and will produce a large amount of sludge, which is difficult to handle. The adsorption method is simple to operate, low-cost, and environmentally friendly. At the same time, it has a good treatment effect on phosphorus-containing wastewater of different concentrations, especially low-concentration phosphorus-containing wastewater, and is a very promising technology.

[0003] Currently, anion exchange resin adsorbents are mainly in the form of powder, which has problems such as difficulty in use, easy loss and difficulty in recovery in engineering applications. Large particles or spherical macroporous anion exchange resins directly loaded into the filter cavity have problems such as low phosphorus removal efficiency and slow phosphorus removal speed. Based on this, the present invention needs to improve the existing phosphorus removal device. Summary of the Invention

[0004] (1) Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a phosphorus removal device with a zirconium-modified anion exchange resin, which can quickly adsorb phosphorus in sewage, remove phosphorus at a fast speed and with stable phosphorus removal efficiency.

[0006] (2) Technical solution

[0007] The technical solutions of the present invention are as follows:

[0008] A dephosphorization device with a zirconium-modified anion exchange resin comprises a fixed bracket and a filter frame, the filter frame being mounted on the fixed bracket. A resin loading module is detachably mounted within the filter frame. The resin loading module has a thickness of 2-10 cm and includes a first side surface and a second side surface. The first side surface is densely covered with honeycomb-shaped filter channels, the filter channels extending along the thickness of the resin loading module and reaching the second side surface. The inner diameter of the filter channels gradually decreases along the thickness of the resin loading module, or gradually decreases to a minimum inner diameter and then expands. The maximum inner diameter of the filter channels is 8-12 mm, and the minimum inner diameter is 2-4 mm. The filter channels are filled with 0.15-0.35 mm of zirconium-modified anion exchange resin, the filling amount being 60-85% of the filter channel volume. Non-woven fabric is laminated on the first and second sides of the resin loading module to block the openings of the filter channels to prevent leakage of the zirconium-modified anion exchange resin.

[0009] According to a preferred embodiment of the present invention, the zirconium-modified anion exchange resin is a zirconium-modified macroporous strong basic styrene anion exchange resin.

[0010] According to a preferred embodiment of the present invention, the preparation method of the zirconium-modified anion exchange resin is as follows: S1, taking a certain amount of macroporous strong basic styrene anion exchange resin (abbreviated as D201 resin), soaking it in 2-4 mol / L hydrochloric acid for 1-3 hours, washing it with deionized water for more than three times, then soaking it in 2-4 mol / L sodium hydroxide solution for 1-3 hours, washing it with deionized water until the pH of the supernatant is neutral, and drying the resin at 40-60°C;

[0011] S2. Mix the resin treated with S1 with a zirconium oxychloride solution having a concentration of 0.1-0.3 mol / L, adjust the pH to >10 with sodium hydroxide, and oscillate at a constant temperature of 45-55°C for 8-12 hours to load the resin with zirconium; after the oscillation, filter, and place in a thermostat at 60°C-80°C for heat treatment for 8-12 hours to obtain a zirconium-modified anion exchange resin.

[0012] According to a preferred embodiment of the present invention, the resin filling module is composed of a first assembly part and a second assembly part, the filtering channel is formed on the first assembly part, and the second assembly part is provided with an assembly hole corresponding to the filtering channel; the second assembly part and the first assembly part are docked and assembled to form a box structure with a cavity inside, a heating cable is provided in the box structure, and the heating cable is wound around the outer wall surface of each filtering channel; the peripheral side of the box structure is provided with wiring holes.

[0013] Preferably, the resin filling module is made of ceramic, stainless steel, fiberglass or plastic.

[0014] According to a preferred embodiment of the present invention, the resin filling module is detachably assembled to the filter frame, and the filter frame is detachably mounted on the fixed bracket; a trapezoidal assembly portion is provided on the side of the filter frame, and a trapezoidal slide is provided on the fixed bracket corresponding to the trapezoidal assembly portion, so that the filter frame and the fixed bracket are easy to assemble and disassemble.

[0015] According to a preferred embodiment of the present invention, the fixed brackets are installed horizontally in pairs, and the fixed brackets are provided with trapezoidal chutes for assembling multiple filter frames, so that multiple filter frames can be assembled in the vertical height direction to achieve the purpose of deep phosphorus removal from phosphorus-containing wastewater.

[0016] According to a preferred embodiment of the present invention, a horizontally placed stainless steel filter is installed in the trapezoidal chute at the uppermost layer to block larger insoluble matter and prevent clogging of the filter frame at the lower layer.

[0017] According to a preferred embodiment of the present invention, the number of the filter frames can be determined according to the phosphorus content in the phosphorus-containing wastewater, and is preferably 3-5.

[0018] When the phosphorus content is too high, the number of filter frames can be increased, and vice versa. As the phosphorus removal time increases, the zirconium-modified anion exchange resin 4 in the top filter frame 8 becomes saturated with phosphate ions. The top filter frame 8 can be removed, the second filter frame 8 can be moved up, and a new filter frame 8 can be added to the bottom layer. The new filter frame 8 is a filter frame that has been replaced with a new resin loading module 6 containing a zirconium-modified anion exchange resin 4.

[0019] (3) Beneficial effects

[0020] The phosphorus removal device with zirconium-modified anion exchange resin of the present invention can be used in the phosphorus removal process of water treatment, which includes the following technical effects:

[0021] 1. By loading zirconium ions on anion exchange resin, the adsorption efficiency of anion exchange resin on phosphorus is greatly improved, and zirconium-modified anion exchange resin is obtained, which improves its selective adsorption performance and phosphorus adsorption capacity.

[0022] 2. The selected anion exchange resin is a macroporous, strongly basic styrene anion exchange resin (D201), which further improves the anion exchange resin's adsorption capacity and adsorption rate for phosphorus and phosphorus removal efficiency.

[0023] 3. Improvements have been made to the plate and frame containing the anion exchange resin. Traditionally, the plate and frame containing the anion exchange resin consists of a box with stainless steel filter screens on both sides. Inside, spherical macroporous anion exchange resin fillers (particle size of 1.2mm or larger) are packed. When adsorbing phosphate ions in water, the impact of the water flow causes the spherical macroporous anion exchange resin fillers to jump / tumble within the box, resulting in poor mass transfer with the phosphate in the water flow and unsatisfactory phosphorus removal results.

[0024] The present invention improves the plate frame and provides a newly designed resin loading module. The resin loading module is provided with a honeycomb-shaped packing of finer (0.15-0.35 mm) zirconium-modified anion exchange resin. On the one hand, anion exchange resin with a smaller particle size can be used, which has a larger specific surface area and is conducive to adsorption. On the other hand, the gradually decreasing inner diameter of the honeycomb filter channel is utilized to gradually increase the pressure of the water flow through the filter, limit the movable space of the anion exchange resin, strengthen the ion mass transfer effect, enhance the adsorption effect of the zirconium-modified anion exchange resin on phosphate, and also reduce the loading amount of the anion exchange resin (only 60-85% of the volume in the filter channel is filled), which is conducive to saving the cost of the anion exchange resin.

[0025] The resin loading module is a reusable modular structure that can be reused after manufacture to save costs. After use, only the anion exchange resin needs to be replaced, and the loading process can be automated. The replaced anion exchange resin, which has been saturated with adsorption, can be regenerated and then loaded and reused.

[0026] 4. An insulating heating cable is provided in the resin filling module and wound around the outer wall of each filter channel. The phosphorus-containing wastewater in the filter channel can be heated by electric heating to strengthen ion exchange and enhance the adsorption of phosphate by the zirconium-modified anion exchange resin, thereby achieving the purpose of deep phosphorus removal. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic cross-sectional structural diagram of the resin loading module in Example 1 of the present invention.

[0028] Figure 2 This is a schematic cross-sectional structural diagram of the resin loading module in Example 2 of the present invention.

[0029] Figure 3 Schematic diagram of the filter frame of the phosphorus removal device according to a preferred embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram of the fixed bracket structure of the phosphorus removal device in a preferred embodiment of the present invention.

[0031] Figure 5This is a schematic diagram of the overall structure of a phosphorus removal device according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0033] like Figure 3-5 As shown, the present invention provides a dephosphorization device with a zirconium-modified anion exchange resin, which includes a fixed bracket 9 and a filter frame 8. The filter frame 8 is mounted on the fixed bracket 9. A resin filling module is detachably mounted in the filter frame 8. The structure of the resin filling module is as shown in FIG. Figure 1 or Figure 2 As shown, Figure 1 is a schematic cross-sectional structural diagram of the resin loading module in Example 1 of the present invention, Figure 2 FIG2 is a cross-sectional structural diagram of the resin loading module in Example 2 of the present invention.

[0034] Example 1

[0035] like Figure 1 As shown, the thickness of the resin filling module 6 is 2-10 cm, and includes a first side 61 and a second side 62. The first side 61 is densely covered with honeycomb filter channels 5. The filter channels 5 extend along the thickness direction of the resin filling module and reach the second side 62. The inner diameter of the filter channels 5 is gradually reduced along the thickness direction of the resin filling module ( Figure 1 A), or first gradually reduce to the minimum inner diameter and then expand ( Figure 1 B). The maximum inner diameter of the filter channel 5 is 8-12 mm, and the minimum inner diameter is 2-4 mm. The filter channel is filled with a 0.15-0.35 mm thick zirconium-modified anion exchange resin 4, and the filling amount is 60-85% of the volume of the filter channel 5 (not completely filled). A layer of non-woven fabric 7 is laminated on the first side 61 and the second side 62 of the resin loading module 6 to block the openings on both sides of the filter channel 5 to prevent leakage and loss of the zirconium-modified anion exchange resin 4.

[0036] Among them, the zirconium-modified anion exchange resin 4 is a zirconium-modified macroporous strongly basic styrene anion exchange resin (abbreviated as Zr-201); the preparation method is as follows: S1, take a certain amount of macroporous strongly basic styrene anion exchange resin (abbreviated as D201 resin), soak it in 2-4 mol / L hydrochloric acid for 1-3 hours, wash it with deionized water for more than three times, then soak it in 2-4 mol / L sodium hydroxide solution for 1-3 hours, rinse it with deionized water until the pH of the supernatant is neutral, and place the resin at 40-60°C for drying; S2, mix the resin treated with S1 with a 0.1-0.3 mol / L zirconium oxychloride solution, adjust the pH to >10 with sodium hydroxide, and oscillate it at a constant temperature of 45-55°C for 8-12 hours to load the resin with zirconium; after the oscillation, filter it, place it in a constant temperature box at 60°C-80°C for 8-12 hours to obtain the zirconium-modified anion exchange resin 4 (Zr-201). The resin filling module 6 is made of ceramic, stainless steel, fiberglass or plastic.

[0037] The resin loading module 6 is removably assembled to the filter frame 8, which is removably mounted to the fixed bracket 9. Trapezoidal assembly sections 81 are provided on the sides of the filter frame 8, and the fixed bracket 9 is provided with a trapezoidal chute 91 corresponding to the trapezoidal assembly section 81, allowing for easy assembly and disassembly of the filter frame 8 with the fixed bracket 9. The fixed brackets 9 are mounted horizontally in pairs, and are equipped with trapezoidal chutes 91 for assembling multiple filter frames 8. This allows for the vertical assembly of multiple filter frames to achieve deep phosphorus removal from phosphorus-containing wastewater. Water flows from above through each layer of filter frames 8, acting under gravity and pressure, and exits at the bottom. The trapezoidal chute 91 on the top layer can be fitted with a horizontally positioned stainless steel filter screen to block larger insoluble matter and prevent clogging of the filter frames below. The number of filter frames 8 can be determined based on the phosphorus content in the phosphorus-containing wastewater, with a preferred number of 3-5. For example, if the phosphorus content is high, the number of filter frames 8 can be increased; otherwise, the number can be reduced. As the phosphorus removal time increases, after the zirconium-modified anion exchange resin 4 in the top filter frame 8 becomes saturated with phosphate ions, the top filter frame 8 can be removed, the second filter frame 8 can be moved up, and then a new filter frame 8 can be added to the bottom layer.

[0038] Example 2

[0039] The only difference between this embodiment and embodiment 1 is that in this embodiment, the resin filling module 6 is composed of a first assembly 63 and a second assembly 64. Figure 2As shown, the first assembly 63 is formed with filter channels 5, and the second assembly 64 has assembly holes 641 corresponding to the filter channels 5, so that the ends of the filter channels 5 of the first assembly 63 can be inserted into the assembly holes 641. Furthermore, when the second assembly 64 is docked and assembled with the first assembly 63, a box structure with a cavity is formed, and the outer walls of the filter channels 5 are accommodated within the box structure. A heating cable 3 is installed within the box structure and is wound around the outer walls of each filter channel 5. A wiring hole 2 is provided on the side of the box structure, and the wires of the heating cable 3 extend through the wiring hole 2 and are connected to a power source. A layer of non-woven fabric 7 is laminated on the first side 61 and the second side 62 of the resin loading module 6 to seal the openings on both sides of the filter channels 5 and prevent the zirconium-modified anion exchange resin 4 from leaking out. The box structure also contains an infrared temperature measuring element, which detects and displays the surface temperature of the outer walls of the filter channels 5 and controls the power supply module of the heating cable 3. This embodiment mainly considers that when the temperature of the treated water is too low, the water temperature can be raised to about 40-50°C by the heating cable to achieve the effect of improving the ion exchange efficiency. When the temperature is too high, the heating is cut off to prevent the temperature from being too high and reducing the ion exchange effect.

[0040] Application Example 1

[0041] In this example, the zirconium-modified anion exchange resin 4 is a zirconium-modified macroporous strong basic styrene anion exchange resin (abbreviated as Zr-201), and its preparation method is as follows: S1. Take a certain amount of D201 resin, soak it in 3 mol / L hydrochloric acid for 1 hour, wash it with deionized water for more than three times, then soak it in 2 mol / L sodium hydroxide solution for 2 hours, wash it with deionized water until the pH of the supernatant is neutral, and place the resin at 50°C for drying; S2. Mix the resin treated with S1 with a 0.2 mol / L zirconium oxychloride solution, adjust the pH to 11 with sodium hydroxide, and oscillate it at a constant temperature of 50°C for 10 hours to load the resin with zirconium; after the oscillation, filter it, place it in a constant temperature box at 60°C for heat treatment for 10 hours to obtain the zirconium-modified anion exchange resin 4 (Zr-201).

[0042] Phosphorus removal by filtration was performed using a single-layer resin-filled module 6 from Example 1. The resin-filled module 6 was made of ceramic and had a thickness of 10 cm. The inner diameter of the filtration channels 5 gradually decreased along the thickness of the resin-filled module to the end, with a maximum inner diameter of 10 mm and a minimum inner diameter of 2 mm. The filtration channels were filled with a zirconium-modified anion exchange resin 4 having an average particle size of 0.2 mm, the filling amount of which accounted for 75% of the volume of the filtration channels 5.

[0043] Application Example 2

[0044] In this example, the preparation method of zirconium-modified anion exchange resin 4 is the same as that in Example 1.

[0045] Phosphorus removal by filtration was performed using a single-layer resin packing module 6 from Example 2. The resin packing module 6 was made of plastic and had a thickness of 10 cm. The inner diameter of the filtration channels 5 gradually decreased along the thickness of the resin packing module to the end, with a maximum inner diameter of 10 mm and a minimum inner diameter of 2 mm. The filtration channels were filled with zirconium-modified anion exchange resin 4 having an average particle size of 0.2 mm, with the filling volume accounting for 75% of the volume of the filtration channels 5. The heating cable 3 was energized to raise the temperature of the filtration channels 5 to 45°C.

[0046] Comparative Example 1

[0047] A box structure with the same thickness and size as the resin loading module was made, non-woven fabrics were set on both sides of the box body, a continuous cavity was formed inside, and it was filled with zirconium-modified anion exchange resin 4 (Zr-201, prepared in the same way as in Example 1) with an average particle size of 0.2 mm to make a filter frame.

[0048] Comparative Example 2

[0049] A box structure with the same thickness and size as the resin loading module was made, non-woven fabrics were set on both sides of the box body, and a continuous cavity was formed inside. The spherical zirconium-modified anion exchange resin 4 (Zr-201, prepared in the same way as in Example 1) with an average particle size of 1.5 mm was filled to make a filter frame.

[0050] Comparative Example 3

[0051] A box structure with the same thickness and size as the resin loading module was made. Non-woven fabrics were placed on both sides of the box to form a continuous cavity inside. The cavity was filled with spherical anion exchange resin (D201, pretreated with hydrochloric acid and sodium hydroxide solution but not zirconium-modified) with an average particle size of 1.5 mm to make a filter frame.

[0052] Prepare a 0.1 M sodium dihydrogen phosphate solution (25° C.) and filter using the filter frames of Application Examples 1-2 and Comparative Examples 1-3 (pre-wetting the filter frames with deionized water). After filtration, measure the concentration of residual phosphate in the water and calculate the phosphorus removal rate.

[0053] Clearance rate = [(initial concentration - concentration after treatment) / initial concentration] * 100%.

[0054] The test results are shown in the following table:

[0055] Group Application Example 1 Application Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Clearance 78.7％ 90.6％ 57.3％ 49.4％ 30.6％

[0056] The above experimental results demonstrate that zirconium-modified anion exchange resin significantly improves the adsorption efficiency of phosphate ions in water compared to unmodified spherical anion exchange resin. Compared to a continuous cartridge-filled cavity, the resin loading module 6 designed in the present invention has a more rational structure. This not only enables the zirconium-modified anion exchange resin to exceed expectations in phosphorus removal from water, significantly improving the adsorption efficiency and speed of zirconium-modified anion exchange resin 4, but also reduces the amount of zirconium-modified anion exchange resin used. When the water temperature is low, the anion exchange resin's phosphorus adsorption efficiency is low, and water has already flowed through before adsorption occurs. The present invention, by using a heating element to raise the water temperature within the filter pores to 40-50°C, further significantly improves phosphorus removal efficiency. Phosphorus removal efficiency can reach approximately 90% with just one layer of resin loading module 6.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A phosphorus removal device with a zirconium-modified anion exchange resin, characterized in that: The invention comprises a fixed bracket and a filter frame, wherein the filter frame is mounted on the fixed bracket; a resin loading module is detachably mounted in the filter frame, wherein the resin loading module has a thickness of 2-10 cm and includes a first side surface and a second side surface, wherein the first side surface is densely covered with honeycomb-shaped filter channels, and the filter channels extend along the thickness direction of the resin loading module and reach the second side surface, and the inner diameter of the filter channels is gradually reduced along the thickness direction of the resin loading module, or is gradually reduced to a minimum inner diameter and then expanded; the maximum inner diameter of the filter channels is 8-12 mm, and the minimum inner diameter is 2-4 mm; the filter channels are filled with 0.15-0.35 mm zirconium-modified anion exchange resin, and the filling amount is 60-85% of the filter channel volume; non-woven fabrics are composited on the first and second sides of the resin loading module to block the openings of the filter channels to prevent leakage of the zirconium-modified anion exchange resin; The zirconium-modified anion exchange resin is a zirconium-modified macroporous strong basic styrene anion exchange resin.

2. The phosphorus removal device according to claim 1, characterized in that: The preparation method of the zirconium-modified anion exchange resin is as follows: S1. Take a certain amount of macroporous strong basic styrene anion exchange resin, soak it in 2-4 mol / L hydrochloric acid for 1-3 hours, wash it with deionized water for more than three times, then soak it in 2-4 mol / L sodium hydroxide solution for 1-3 hours, rinse it with deionized water until the pH of the supernatant is neutral, and dry the resin at 40-60°C; S2. Mix the resin treated with S1 with a zirconium oxychloride solution having a concentration of 0.1-0.3 mol / L, adjust the pH to >10 with sodium hydroxide, and oscillate at a constant temperature of 45-55°C for 8-12 hours to load the resin with zirconium; after the oscillation, filter, and heat-treat in a thermostat at 60°C-80°C for 8-12 hours to obtain a zirconium-modified anion exchange resin.

3. The phosphorus removal device according to claim 1 or 2, characterized in that: The resin filling module is composed of a first assembly part and a second assembly part. The filtering channel is formed on the first assembly part, and the second assembly part is provided with an assembly hole corresponding to the filtering channel. After the second assembly part is docked and assembled with the first assembly part, a box structure with a cavity inside is formed. A heating cable is provided in the box structure, and the heating cable is wound around the outer wall surface of each filtering channel. Wiring holes are provided on the peripheral side of the box structure.

4. The phosphorus removal device according to claim 3, characterized in that: The resin filling module is made of ceramic, metal, fiberglass or plastic.

5. The phosphorus removal device according to claim 1, characterized in that: The resin filling module is detachably assembled to the filter frame, and the filter frame is detachably mounted to the fixing bracket; a trapezoidal assembly portion is provided on the side of the filter frame, and a trapezoidal slide is provided on the fixing bracket corresponding to the trapezoidal assembly portion, so that the filter frame and the fixing bracket are easy to assemble and disassemble.

6. The phosphorus removal device according to claim 5, characterized in that: The fixing brackets are installed horizontally in pairs, and the fixing brackets are provided with trapezoidal slides for assembling a plurality of filter frames, so that a plurality of filter frames can be assembled in a vertical height direction.

7. The phosphorus removal device according to claim 6, characterized in that: A horizontally placed stainless steel filter is installed on the uppermost trapezoidal chute to block larger insoluble matter and prevent clogging of the filter frame below.

8. The phosphorus removal device according to claim 6, characterized in that: The number of the filter boxes is 3-5.

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